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Tuesday, 15 April 2008

The Hinxton Group on Science, Ethics and Policy Challenges of Pluripotent Stem Cell-Derived Gametes
Tuesday, 15 April 2008
The Hinxton Consortium, which was formed in 2004 to investigate the ethics and legality of stem cells, yesterday issued its recommendations for how research aimed at creating artificial gametes – sperm and eggs – should proceed.
They warn politicians not to block scientific inquiry into subjects such as stem cells and embryo research just because there is a difference of opinion on the ethics or morality of the work. They also said that moral disagreements in society should never be used on their own to stop scientific investigation.
"Societies have the authority to regulate science, and scientists have a responsibility to obey the law. However, policy-makers should refrain from interfering with scientific inquiry unless there is a substantial justification for doing so that reaches beyond disagreements based solely on divergent moral conviction. Any interference with scientific inquiry should be derived from reasonable concerns about demonstrable risks of harm to persons, societal institutions, or society as a whole," the consortium said.
Scientists are working on a number of ways of making stem cells derived from embryos, or ordinary tissue such as skin, and turning them in the laboratory into mature sperm and eggs that could then be used in IVF clinics for fertility treatment. In Britain, the Human Tissues and Embryo Bill, that is currently making its way through Parliament, would allow research into human artificial gametes but further changes to the law would be needed to allow doctors to use such sperm and eggs on patients.
Professor John Harris, a bioethicist at Manchester University who is part of the consortium, said that while the development of artificial sperm or eggs to treat infertile couples was still a long way off, it is important the work is not blocked from the start.
"At this stage the real ethical issue is to ensure that the science can continue... Is society ready for it? We don't know that, and of course if it isn't, then it won't happen, but there is probably some considerable time in which this could be discussed," Professor Harris said.
"Any tool can have applications that people can object to, from kitchen knives to anything else."
The research has also prompted speculation that sperm could be produced from a woman or eggs from a man, allowing lesbian or gay couples to have children to whom both partners make an equal genetic contribution. One possible way of making sperm and eggs would be to engineer them from skin cells.
Researchers, however, dismissed the prospect of male eggs and female sperm as science fiction in the new Hinxton group report. Professor Robin Lovell-Badge, of the National Institute for Medical Research in London, and a member of the group’s steering committee, said there may be insuperable barriers to the possibility of one sex making both types of gametes.
“It would be very difficult to get eggs from XY cells, and even more difficult to get sperm from XX cells – my own view, indeed, is that the latter is impossible.”
Human sex is determined by the inheritance patterns of the X and Y chromosomes: women have two copies of the X, while men have one X and one Y. As several genes that are critical to sperm production are carried on the Y chromosome, this will make it “difficult or even impossible” to turn female cells with two X chromosomes into sperm under any circumstances currently known to science.
The production of eggs from male cells is a little less problematic, but even this is likely to be “very difficult”, the report said.
Reference:
Consensus Statement: Science, Ethics and Policy Challenges of Pluripotent Stem Cell-Derived GametesThe Hinxton Group.........
ZenMasterFor more on stem cells and cloning, go to CellNEWS at
http://www.geocities.com/giantfideli/index.html